Retractable ball-point pen



Aug. 28, 1962 Filed June 8, 1959 J. M. SCHWARZAUGL RETRACTABLE BALL-POINT PEN 2 Sheets-Sheet 1 INVENTOIQI Pa Ze f 14,011

1962 J. M. scHwARzAuGL 3,051,131

RETRACTABLE BALL-POINT PEN 2 Sheets-Sheet 2 Filed June 8, 1959 a Wm M E: 1 W 2 A v M g w m N. w m w. w m. m s w gs agasa d J h 3 .m

3,051,131 Patented Aug. 28, 1962 3,051,131 RETRACTABLE BALL-POINT PEN V Josef Maria Schwarziiugl, Stein near Numberg, Germany,

assignor to A. W. Faber-Castell, Stein near Numberg,

Germany, a firm of Germany Filed June 8, 1959, Ser. No. 818,598 Claims priority, application Germany June 11, 1958 2 Claims. (Cl. 12042.03)

The present invention relates to a ball-point pen comprising a tubular casing with a retractable ball-point insert therein carrying a retracting spring and a push button projecting from the rear end of the casing and carrying a locking member which connects the pushbutton with the rear end of the ball-point insert and which, when the pushbutton is depressed and the insert is thereby advanced to the writing position against the action of the retracting spring, is moved by the resilient pressure of the ball-point insert into a locking engagement with a part of the casing so as to maintain the insert in the writing position.

The ball-point pens known prior to this invention had the disadvantage that the locking mechanism was relatively complicated and consisted of a plurality of parts which were difiicult to produce and easily became defective, for example, by the fatique of the material of these parts, such as spreading springs, whereby the entire ballpoint pen became useless.

' It is an object of the present invention to provide a retractable ball-point pen with a very simple locking mechanism which does not contain any spreading springs or similar means which are liable to break or become easily worn, and which aside from the pushbutton only consists of one additional part or pair of parts which are very easily manufactured and reliable in operation.

For attaining this object, the pushbutton of the retractable ball-point pen is provided with a locking member which has a locking projection on its lower end and an inclined cam edge adjacent thereto. When the pushbutton is depressed, the upper end of the ball-point insert is pressed by the action of the retracting spring against the inclined cam edge and thereby shifts the locking member outwardly so that the locking projection thereon engages with a suitable abutment on the inside of the casing and thus maintains the ball-point insert in the writing position. If a lateral pressure is then exerted upon the upper end of the locking member, the locking projection may be easily disengaged from the abutment so that the retracting spring can retract the ball-point insert into the casing and thereby also move the pushbutton to its outwardly extended position.

A very simple embodiment of the invention consists in providing the pushbutton of a hollow construction with a pair of opposite slots in its side wall near the upper and lower end thereof, and in inserting into this hollow push button a locking member in the form of a substantially S-shaped arm which has a locking projection at its lower end which extends through the lower slot in the wall of the pushbutton and is adapted to snap underneath an abutment on the inner wall of the casing when the pushbutton is being depressed. Adjacentto the locking projection, the lower end of the locking arm has an inclined cam edge against which the rear or upper end of the ball-point insert engages under the resilient pressure of the retracting spring and thereby moves the lower end of the locking arm outwardly so that the locking projection will remain in engagement with the mentioned abutment. The upper end of the S-shaped locking arm projects through the upper slot in the wall of the pushbutton so that, when a lateral pressure is exerted upon this upper end of the locking arm, the lower locking end will be withdrawn from the abutment, permitting the retracting spring to retract the ball-point insert into the casing. The upper end of the insert which engages with the cam edge of the locking arm will at the same time move the pushbutton to its outwardly extended position.

According to a further embodiment of the invention, the pushbutton is made of two parts and designed similar to a pair of tongs or pliers. Each of these parts has a locking projection at its lower end and an adjacent inclined cam edge. Both of these cam edges engage under the resilient pressure of the retracting spring with the edge of the rear end of the ball-point insert at diametrically opposite points thereof so that the combined action of these cam edges upon the insert will always be central relative to the insert.

These and other objects, features, and advantages of the present invention will be further apparent from the following detailed description thereof, particularly when read with reference to the accompanying drawings, in which:

FIGURE 1 shows a longitudinal section of a ball-point pen according to the invention with a locking member in the hollow pushbutton thereof and with the ball-point insert in the released or retracted position;

FIGURE 2 shows a cross section taken along line IIII of FIGURE 1;

FIGURE 3 shows a longitudinal section of the ballpoint pen according to FIGURE 1 but with the ballpoint insert in the writing position;

FIGURE 4 shows a longitudinal section of a modification of the ball-point pen according to the invention with a two-part pushbutton in the retracted position of the ball-point insert;

FIGURE 5 shows a cross section taken along line VV of FIGURE 4; while FIGURE 6 shows a longitudinal section of the ballpoint pen according to FIGURE 4 but with the ball-point insert in the writing position.

Referring to the drawings, and first particularly to FIGURES 1 to 3, the ball-point pen according to the in-' vention consists of a tubular casing 1 forming the holder of a ball-point insert 2 which may be locked in an advanced writing position within casing 1 or retracted into the casing by the action of a retracting spring 3. The front end of this retracting spring 3 rests upon an inner shoulder in the tip of casing 1 and acts with its rear or upper end against a small flange 2" on the insert 2. The rear end of the tubular casing 1 is closed by a cap 6 which has a central bore in which a hollow pushbutton 4 is slidable in the axial direction. The lower end of pushbutton 4 has an outwardly projecting flange 4" which is adapted to engage with the lower end 6 of cap 6 when it is in the upward position. The hollow pushbutton 4 contains a substantially S-shaped locking member 5, the upper end portion 5 of which projects from the pushbutton through an opening 4' in the wall thereof, while the lower end 5" forms a locking portion 5" which projects in the opposite direction from portion 5' through another opening 4" in the wall of pushbutton 4. An inclined cam edge 5" on locking member 5 adjacent to locking portion 5" engages with the upper end 2' of ball-point insert 2 which is pressed in the upward direction by spring 3. By such a resilient pressure of insert 2 upon the cam edge 5" pushbutton 4 is pushed upwardly, while the locking member 5 is shifted laterally to press the locking portion 5" against the inner Wall of the bore of cap 6. If a pressure is exerted upon the outer end of pushbutton 4, the ball-point insert 2 will be pushed forwardly until locking portion 5" under the resilient pressure of insert 5 against cam edge 5" snaps underneath the lower edge 6' of cap 6, as shown in FIGURE 3, where it is securely maintained by the tendency of locking member 5 to pivot outwardly, whereby insert 2 is also securely maintained in the advanced or writing position. In order to retract insert 2 3 into casing 1, a lateral pressure is exerted upon the pro jecting portion of locking member 5 whereby the looking portion 5" will be retracted from the lower edge 6' of cap 6, whereupon spring 3 presses insert 2 and thus also pushbutton 4 upwardly until flange 4" on the lower end' of the latter engages with the lower end 6' of cap 6.

In the modified embodiment of the invention as illustrated in FIGURES 4 to 6, the end cap 8 is secured to casing 1 by means of a threaded bushing 7 which also serves as a guide for maintaining the ball-point insert 2 in a central position within casing 1a. The central bore in cap 8 has two inner enlarged recesses so as to form two shoulders 8' and 8". Pushbutton 9, is made of two parts similar to a pair of pliers with the upper end portion projecting from cap 8 being divided longitudinally and adapted to open and close. Whereas the locking member 5 of pushbutton 4 of the embodiment according to FIG- URES l to 3 has only one cam edge 5"", the pushbutton 9, 10 according to FIGURES 4 to 6 is provided with two cam edges, namely, a cam edge 9 and 10' on the lower end of each of the pushbutton parts 9 and 10, respectively.

When the ball-point insert 2 is retracted, the two pushbutton parts 9 and 10 engage with each other and the locking projections 9", 10" on the lower ends thereof engage with the wall of the bore in cap 8. A flange 9" on the pushbutton part 9 then engages with shoulder 8" in the wall of the bore ofcap 8 and thereby prevents the twopart pushbutton 9, 10 from falling out of the bore. Under the action of spring 3, the upper end 2' of insert 2 presses against the cam edges 9 and 10' and thereby pushes the two pushbutton parts 9 and 10 apart and the outwardly projecting ends 9" and 10' against the wall of the bore in cap 8.

If a downward pressure is exerted upon the retracted pushbutton 9, 10, the ball-point insert 2 is pushed forwardly until the two projecting ends.9" and 10" snap underneath the lower shoulder 8' in cap 8, as shown in FIGURE 6, and lock insert 2 in the writing position. For retracting insert 2, the two. pushbutton parts 9 and 10 are pressed together so that the locking projections 9" and 10" will be withdrawn from shoulder 8', whereupon spring 3 can retract insert 2 as well as pushbutton 9, 10 until flange 9" engages with the upper shoulder 8" in cap 8, as shown in FIGURE 1.

Flange 9" is preferably provided with, a conical surface, which is adapted to engage with a corresponding conical surface of shoulder 8" and thereby tends to press the two parts 9 and 10 of .the pushbutton toward each other.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully described my invention, what I claim l. A ballpoint pen comprising, in combination: a tubular casing having a rear end and an annular shoulder within said rear end; a ball point insert within said casing; a retracting spring acting upon said insert for retracting the same into said casing from an advanced writing position to a retracted position; a tubular hollow push button closed at its outer end and having an outwardly directed flange at itsopposite inner end, said push button being slidably mounted within said rear end of said casing, said flange of said push button engaging in said retracted position of said insert said annular shoulder within said rear end of said casing, said push button having a wall provided with a first aperture above said rear end of said casing and a second aperture near said flange; a flat and substantially S-shaped locking member loosely arranged within said hollow push button, said locking member having an upper actuating end portion extending radially outwardly through said first aperture and a lower end portion provided with an inclined cam surface engaging with said rear end of said insert under the resilient pressure of said retracting spring for pressing said lower end portion radially outwardly; and a locking shoulder provided at said lower end portion of said locking member, said locking shoulder projecting through said second aperture and engaging underneath said annular shoulder within said casing when said push button is depressed to maintain said insert in said advanced writing position thereof.

2. A ball-point pen comprising, in combination: a tubular casing having a rear end; a cap detachably connected to said rear end of said casing for closing the same, said cap having a central bore as well as an inwardly projecting face; a ball point insert within said casing; a retractingspring acting upon said insert for retracting the same into said casing from an advanced writing position to a retracted position; a tubular hollowpush button closed atone end and having an outwardly directed flange at its other end, said push button being slidably mounted-within said central bore of said cap, said inwardly projecting face of said cap forming an annular shoulder serving as an abutment for said outwardly projecting flange of said push button in said retracted position, said push button having a wall provided with a first aperture'above said rear end of said casing and a second aperture near said flange;

a flat locking member loosely arranged-within said push' button, said locking member having anupper actuating portion extending outwardly through said first aperture and having a lower end portion provided with an inclined cam surface engaging with saidrear end of said insert under the resilient pressure of said retracting spring for pressing said locking member outwardly and upwardly into engagement with the upper edge of said upper aperture; and a locking shoulder provided at said lower end portion. of said locking member extending through said second aperture to engage said shoulder of said cap when said push button is pressed into said casing, the upper edge of said upper aperture forming a pivot point for said locking member whenbeing moved into locking position, while the upper edge of said lower aperture forms a pivot point when said actuating portion of said locking member is moved inwardly, thereby unlocking said locking shoulder.

References Cited inthe file of this patent UNITED STATESVPATENTS 2,741,226 Dietrich et ah Apr. 10, 1956 2,800,882 Smith July 30, 1957- 2,823,645 Johnson Feb. 18, 1958 2,929,360 Smith Mar. 22, 1960 FOREIGN PATENTS 4,254 Great Britain 1889 805,573 Great Britain Dec. 10, 1958 

